Yes, if I can't sleep in, it ain't my revolution! etc. I don't know about you, but early's never been my scene. Indeed, I was just recalling the other day, when I was younger, in me carefree 20s with fewer responsibilities to other humans, my normal hours of sleep were 4am to 12pm.
Time and circumstance has modified all that, of course; now its 2am to 8.30am. Cutting back on sleep hasn't really led to any productivity gains though - I rarely have a sentient thought before 10am. My brain still gets 8 hours, though the body has learned sleep-dressing and transport management.
I can't really help it, and to be honest, I don't want to change. These hours of solitude and focus have been the most productive of my life. I reckon I wrote most of my PhD between 10pm and 1am. I guess I'd like to know there are others out there still staying up, despite careers and so on. Perhaps well into middle age!
For example, I suspect my men HET here, princes of Dutch 60s freakbeat, still kick it late*. Now that semester two is nearly done I'm hoping to be back here (at Fort Segue) more often. Check it out!
* Hat tip to my bro, aka The World of Yentl, for putting me on to this ace track.